Abnormal potential-discharging and arc-disrupting device.



F. W. ERIGKSON & F. W. LORD. ABNOBMAL POTENTIAL DISGHARMNG AND AncDISRUPTING DEVICE. APPLICATION FILED APB..27, 1907.

932,541 Patented Aug. 31, 1909.

"UNITED srATEs rATEN'r EEicE.

FREDERIC WM. vIERICKSCN AND FREDERIC W.A LORD, 0F NEW YORK, N. Y.

AENOR/MAL POTENTIAL-DISCHARGNG AND ARC-DISRUPTING DEVICE.

To all whom it may concern:

Be it known that we, FREDERIC VM. Erickson and F REDERie lV. LoRD,residing` at New York, in the county of New York and State of New York,haveinvented certain Improvement-s in Abnormal Potential- Dischargingand Arc-Disrupting Devices, of which the following is a specification.

In overhead electric transmission lines trouble is often experienced incentral stations and sub-stations by lightning striking the line orstriking near the line. This causes a wave of current of very highpotential to momentarily flow over the line to the station and do damageto the electric apparatus therein. Similar trouble is caused by socalled static charges on the line, as well as by short circuits, suddenchanges of load, etc. All damage so caused may be avoided if lan easypath to earth or ground is provided before any such abnormal wave ofcurrent reaches the station. It has been found that this extraordinarysurge of current may be easily carried to earth, by connecting to theoverhead line an electrode or terminal, and placing opposite and nearthereto, but not touching it, a second terminal or electrode which inturn is grounded or connected to earth. It has been found, however, thatthis static discharge or abnormal surge of current will cause a spark tojump across these terminals, thereby furnishing a path of relative lowresistance to earth, which, as is well known, is due to the volatilizedparticles of the electrode made by the spark. This low resistance path,once established, will result in the heavy discharge and flow of thenormal current over it, as evidenced by the so-called following arc.This following arc is most difficult to extinguish, and the inventionwhich we are about to describe provides a combination of terminals, oneof which is connected to earth and the other connected to theoverheadline that is to be protected, and a means to quickly andeffectually dissipate and extinguish the following are which the normalline current tends to sustain.

A special feature of the invention therefore is to provide means whichwill permit the immediate passage to earth of the static charge comingon the line, and which will obstruct and eliminate the followingcommercial current flowing in the circuit, and the means which we havedevised consist-s in the use of a highly insulating, non-infiam-Specieation of Letters Patent.

Application filed April 27, 1907.

Serial No. 370,567.

mable porous material such as asbestos in the form of a disk to berapidly rotated between the line electrode and the ground electrode; wemay use a disk of harder insulation such as porcelain.

The invention therefore consists in the provision of a path from theline to earth for the static charge, and for breaking up this initialpath to prevent the regular .line current from continuing therethroughto earth. After the static current or charge has passed to earth, thecommercial current in the line will endeavor to pass over the path ofthe volatilized metal particles, but will suppress an initial arcvirtually coincident with its formation, as the rotating drop will bythe interposition of its relatively cold substance eliminate the arc.

Of the drawings, which form a part of this specification and illustratethe invention, Figure l is a side view of the invention operating inair. Fig. 2 is a side view of the invention operating in oil. Fig. 3 isa plan view of the disk or rotor. Fig. 4; a side view of anamplification of the invention with multiple disks. Fig. 5 is a sideview of a modification. Fig. (3 is a sectional view of a modificationshowing the reversibility of the parts.

In Fig. l the electrode 9 is connected by the conductor l2 to theover-head line which is to be protected. This electrode is held by aninsulated support l0 mounted on base l. The electrode 9 is capable ofvertical adjustment by means of set screw l1. The lower terminal, orelectrode is connected to earth by conductor 8. lt is supported by aninsulated standard G mounted on base l and capable of verticaladjustment by means of set screw 7. On base l is mounted a driving motor2, which is preferably an electric motor, but it may be any suitablesource of power. This motor 2 furnishes continuous rotation to shaft 3,which in turn causes the disk 4- to revolve. The construction and motionof this disk forms the essential part of the apparatus. The disk may beconstructed of a highly insulating, porous material such as asbestos, orof non-porous material as porcelain. lf the disk be of a porous, highlyinsulating material such as asbestos, the size of the electrodes is'notmaterial. provided they are of at least the. carrying capacity of theconductors l2 and S. Vith this construction the path from the overheadline to earth is Patented Aug. 31, 1909.

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through the conductor 12, through the electrode 9, through the porousdisk from electrode 9 to electrode 5, through electrode 5, throughconductor 8 to earth.

1t will be seen from the above description that with either form ofdisk, there is an easy path from the overhead line to earth, interceptedonly by the disk, which offers no greater static discharge barrier thanif there were no disk of any form between the electrodes 9 and 5. Thiswe have found by extensive experiment to be true, because the sparkcaused by the abnormal surge of current will jump from electrode 9 to 5equally readily with no disk between the electrodes or with either formof disk revolving at a high rate of speed between the electrodes. liththe porous material, such as asbestos, t-he spark will jump through theporous material as it will not act as a static discharge barrier, therebeing a sufficient air space around the fibers of the naterial throughwhich the spark will pass. There the disk is of non-porous material, thecurrent-path extends over the edge of the disk, the latter being solocated with respect to the electrodes as to place the electrodes inclose proximity to the perimeter of the disk, as indicated in thedrawings.

le have found that the so-called follow ing arc 7 of the normal workingcurrent will not, as we explained above, follow this low resistance pathmade by the spark, on account of the fact that the disk revolving at ahigh rate of speed will instantly carry away and dissipate thevolatilized portions of the electrodes made by the spark as it passes.1f the disk were at rest this low resistance volatilized conducting pathwould remain undisturbed and the following normal current would veryshortly melt the electrodes and cause damage by a virtual short circuitof the overhead system to ground. "With the disk in motion, however,this following arc is attenuated and extinguished at its very inception,on account of the immediate displacement of this low resistancevolatilized conducting path by the relatively cold porous or non-poroussubstance of the disk as the case may be. l

The above description illustrates the principle of our device in asimple form. There might be many modifications of the above idea, suchas having the revolving disk rotate in a bath of insulating oil, asillustrated in Fig. Q, in which the motor 2 is mounted on the base 1,the motor driving shaft 3, which is connected to disk 4, revolvingbetween electrodes 5 and 9, all substantially as described in Fig. 1.

1n F ig. :2 the base 1 is supported on a subbase 15 by means ofstandards 1i, 111A. The tank 1B, 1? being set on sub-base 15. This tankmay be of any insulating material such as glass, this we have foundserving as a practical means of containing the oil, at the same timeallowing the attendant to watch the operation of the device through thesides of the tank. Another form of device which would furnish acontinuous motion of the porous material, such as asbest-os, passingbetween the electrodes G and 9, is shown in F ig. 5, in which 4a is abelt. 1n

Ythis case it might be advisable to have an intermediate conductingelectrode 16 in order to be able to easily regulate the total sparkingdistance between electrode G and electrode 9. 1t is apparent that thesame results would be obtained by having the intervening porousmaterial, such as asbestos, or non-porous material, such as porcelain,remain stationary, furnishing a continuous movement of the electrodes asshown by Fig. 7. 1n this instance the underlying principle would be inno manner affected as Vthere would be provided a rapid relative motionof the electrodes and the intervening material. This construction wouldbe more complicated than such a device as indicated in Fig. 1, but wemention it to bring out the fact that it is immaterial whether theelectrodes move or whether the intervening substance moves; in eachinstance the path of the arc would be continuously interrupted byunheated insulating non-inflammable material.

1n Fig. 4C we show a plurality of disks upon a shaft 3, connected to amotor, and a series of electrodes between the disks in order to morequickly, if necessary, eliminate the arc following a static charge. ltsoperation will be seen without specific description.

1n each of the forms shown, it will be seen that the insulating materialextends bet Teen and has its motion in a direction at substantial rightangles to the plane of the axis of the electrodes.

l'ilhile we have shown several different ways in which the invention maybe applied, in each form shown there is comprised two elements locatedintermediate the point of connection of the wires leading respectivelyto the line to be protected and the ground, these elements being theelectrodes and the are-dissipating device. One of the elements ismovable relatively to the other, but while se movable the elementsretain their positions permanently relatively to each other. And owingto the relative positions of these elements both may be said to belocated within the current path leading from the wire to be protected tothe ground.

As shown in the drawings, the planes of the faces of the opposingelements the terminals and the dissipating device) are in parallelism,and, with the exception of the construction shown in Fig. 5, retain suchparallelism during the movement of the dissipating device. This fact,and the fact that the axis of the motor is located out of alinement withthe terminals, permits of the use ot a dissipatng device of any desireddiameter, or in the form shown in E ig. 5, per mits the driving pulleysfor the belt to be spaced any preferred distance apart, withoutrequiring the use ot widely spaced terminals. In view ot the fact thatthe successful operation ot this character of devices depends greatlyupon the presentation of a relatively cold surface between theterminals, it will be understood that the particular structures shownherein permit ot the obtaining of this result by reason of the abilityto retain the portion ot the dissipating device which has j ust passedbetween the terminals, ont of the current path for a maximum period,controlled by the diameter otl the disk or the space between the pulleysshown in Fig. 5, without attecting the speed at which the `dissipatingdevice is required to move in order to etliciently dissipate the are,the sizes of the disk and the distance between the pulleys shown in Fig.5 being determined by the conditions oiC use.

We claim as our inventionl. An abnormal-potential discharging andarc-disrupting device comprising` two elements mounted in a current pathextending trom the portion ot the circuit to be protected to the ground,one of said elements comprising an arc-dissipating device et larger areathan a cross sectional area of the current path to provide an extendeddissipating path, portions of which are succes` sively positionablewithin the current path, and one ot said elements being constantlymovable, the planes ot' the faces of said elements being` parallel witheach other and rc` maining substantially unchanged relative to eachother, the successive positioning of any given point oit the dissipatingdevice within the current path being at spaced time intervals ofsutlicient length to permit the remaining dissipating portions to bepositioned within the current path.

2. An abnormal-potential discharging and arc-dissipating devicecomprising two elements mounted in a current path extending from theportion of the circuit to be protected to the ground, one of saidelements consisting ot a disk et insulating material extending withinthe current path, said disk being of larger area than a cross sectionalarea of the current path to provide an extended dissipating path,portions of which are successively positionable within the current path,and means for imparting a rotative movement to said disk, the successivepositioning of any given point of the disk within the current path beingat spaced intervals of suliicient length to permit the remainingarc-dissipating portion of the disk to be positioned within the currentpath.

3. An abnormal-potential discharging and arc-dissipating devicecomprising two elcments mounted in a current path extending from theportion et the circuit to be protected to the ground, one of saidelements consisting of a disk ot' insulating porous material extendingwithin the current path said disk being of larger area than a crosssectional area of the current path to provide an extended dissipatingpath, portions of which are successively positionable within the currentpath, and means tor imparting a rotative movement to said disk, thesuccessive positioning of any given point of the disk within thecurrentpath being at spaced inter vals of sniiicient length to permitthe remaining arc-dissipating portion ot the disk to be positionedwithin the current path.

t. In an abnormal-potential discharging current path having spacedterminals therein, and also having intervening current-conu ductingmeans intern'iediate the terminals and spaced therefrom, anarc-dissipating device having a plurality of disks extending Within thecurrent path intermediate the terminals and the interveningcurrent-conducting means, and a motor for imparting simultaneousmovement to each of said disks.

In testimony whereof, we have signed our names to this specification inthe presence of two subscribing witnesses, this 22d day ot April 1907.

FREDERIC IVM. ERICKSON. FREDERIC IV. LCRD. lVitnesses HARRY A. CURTIS,FRANK IV. GAmusoN.

